What is Good for Waterfowl Also Can Be Good for Wild Turkeys
Photos unless otherwise identified by Kathy Andrews Wright and by Mike Sertle
A 2014 report produced by the U.S. Forest Service’s (USFS) Northern Institute of Applied Climate Science (NIACS) identified wet bottomland forest as being one of the habitats most vulnerable to climate change. One such habitat is Oakwood Bottoms, a 4,700-acre forested wetland management unit of the Shawnee National Forest located in southwest Jackson County where the Big Muddy River and Mississippi River floodplains meet.
Oakwood Bottoms is a greentree reservoir, or a stand of bottomland hardwood forest that is shallowly flooded in the fall and winter via a system of berms, pumps and water control structures. The USFS uses these systems to manage water levels in 28 forested impoundments and six smaller moist soil units for waterfowl, turkeys and other wildlife. This water management capability is critically important for addressing what NIACS identified as being the greatest climate-related threat to wet bottomland forests caused by a change in precipitation patterns that will increase the severity of both seasonal flooding and seasonal droughts, wetland vegetation communities and migration patterns across the Central Hardwoods region, which includes most of southern Illinois, southern Missouri, Kentucky and southern Indiana.
“The main objective of a greentree reservoir is to provide food, especially acorns, moist soil plant seeds and aquatic invertebrates, and cover for migratory waterfowl,” explained Steve Widowski, retired USFS wildlife biologist. “The primary species utilizing Oakwood Bottoms during the fall and winter seasons are wood ducks and mallards, but I also have observed black ducks, northern pintail, gadwall, blue- and green-winged teal, northern shoveler, ring-necked duck and hooded merganser on the site.”
Indeed, survey results indicate that during the fall and winter seasons tens of thousands of waterfowl use Oakwood Bottoms, feeding on pin oak acorns and other hard mast to build fat reserves and improve body condition. In addition to waterfowl, the wet-mesic floodplain forest also supports thousands of migratory shorebirds, wading birds and neotropical songbirds. An abundance of cavity trees, and year-round water from ditches and borrow ponds, provide nesting and brood rearing habitat for wood ducks and hooded mergansers.
The rich bottomland soils at Oakwood Bottoms and the surrounding area results in a highly productive habitat for a diversity of other wildlife species. Wild turkeys and white-tailed deer are common, especially in late spring, summer and fall after water drawdowns and before flooding, and can be found year-round foraging on the levees.
“One third of the year Oakwood Bottoms provides excellent habitat for waterfowl,” explained John Burk, National Wild Turkey Federation (NWTF) district biologist for Illinois and Missouri. “After seasonal flood waters recede, wild turkeys find excellent food resources and heavily utilize the forest in spring and summer.”
Oakwood Bottoms has been designated by the Audubon Society as an Illinois Important Bird Area based on the value of the area for waterfowl, shorebirds and breeding yellow-crowned night-herons, a state endangered species. More than 200 species of birds have been documented there, including black-necked stilt, king rail (state endangered), fish crow, Mississippi kite (state threatened), Louisiana waterthrush and prairie warbler.
Other mammals commonly observed in the area include gray and fox squirrels, beaver and muskrat; uncommon sightings include bobcat and river otter. An abundance of small mammals provide foods for organisms higher on the food chain. A wealth of insects and numerous snags and dead trees support several species of rare bats, including summer maternity colonies of little brown bats, the federally threatened northern long-eared and the federally endangered Indiana bats.
Within the last 5 years, Ducks Unlimited (DU) has obtained nearly $2.3 million in federal, state and private grant funds which have been supplemented by additional partner funding from the NWTF and USFS. These organizations have worked to restore and enhance more than 2,250 acres of bottomland forest habitat by selective thinning, supplemental hardwood planting on higher elevation floodplain sites, creation of oak openings and vernal pools, and upgraded wetland management infrastructure.
“With an important mid-latitude location in the Mississippi Flyway, Oakwood is important to both fall and spring migrating, and wintering waterfowl,” added Michael Sertle, DU’s regional biologist for Illinois. “In addition to providing important stop-over habitat for these birds, Oakwood also is an important site for the local waterfowl hunting community.”
Oakwood Bottoms is identified in the Illinois Wildlife Action Plan Forest and Woodland Campaign as one Illinois forest to be monitored to help biologists and land managers understand the responses of wildlife populations to forest management activities and identified by the Wetlands Campaign as a highest priority site.
One ongoing monitoring effort is the work of Dr. Jeff Hoover, avian ecologist with the Illinois Natural History Survey, who has been monitoring avian responses to selective thinning, prescribed fire and other forest stand improvement projects at Oakwood Bottoms. Early results show a promising positive response by several forest-dependent birds, including red-shouldered hawk, red-headed woodpecker, yellow-billed cuckoo, prothonotary warbler, Kentucky warbler and yellow-breasted chat. Another study started in February 2019 by Dr. Mike Eichholz, professor at Southern Illinois University-Carbondale, is utilizing a drone to survey for waterfowl. This survey will help biologists gain knowledge of the importance of Oakwood Bottoms for the spring migration of waterfowl.
The Shawnee National Forest also is working with the U.S. Army Corps of Engineers on planning and implementing even more improvements on the Oakwood Bottoms greentree reservoir in the future to ensure it functions more naturally as a floodplain forest wetland and to maintain its forest and wetland diversity for the long term.
“Oakwood Bottoms is a great place to immerse oneself in nature and wildlife whether you are a hunter, birdwatcher or nature enthusiast,” Widowski concluded. “In decades of visits to the site I could always count on seeing animals there, and truly consider it a wildlife jewel of the Shawnee National Forest.”
Kathy Andrews Wright is retired from the Illinois Department of Natural Resources where she was editor of Outdoor Illinois magazine. She is currently the editor of Outdoor Illinois Wildlife Journal and Illinois Audubon magazine.